BIOA1H3 F - Module 3: Lecture 04

Catabolic pathways

Catabolic pathways

The breakdown of molecules into smaller units, such as in the pathways of glycolysis and the citric acid cycle.

Amatoxins

Toxins found in mushrooms like Amanita phalloides that selectively inhibit RNA Polymerase II, an essential enzyme in mRNA synthesis.

Chemical Reactions

Involve the breaking and forming of chemical bonds, altering the bonds while maintaining the identity and integrity of atoms.

Free Radicals (Reactive Oxygen Species)

Highly reactive and unstable atoms or molecules with unpaired electrons that can cause damage to cells and tissues.

Antioxidants

Substances that provide electrons and reduce oxidative damage to cells and molecules, such as selenium.

Gibbs Free Energy

The energy available to do work in a system, determining whether a reaction is spontaneous (exergonic) or non-spontaneous (endergonic).

Energetic Coupling

A process where spontaneous reactions drive non-spontaneous reactions.

Intermediate ΔG

Determines whether ATP will be produced or consumed, allowing ATP to drive reactions and be replenished.

Activation Energy

The energy input required for a reaction to reach the transition state, which is unstable and has higher energy compared to other states.

Enzyme-Catalyzed Reactions

Chemical reactions in the body that are sped up by enzymes, which possess an active site where substrates bind and are converted to products.

Active Site Formation

The specific amino acids in the enzyme that compose the active site, which are brought close together through protein folding.

Enzyme Specificity

The ability of enzymes to recognize and bind to specific substrates based on the structure of the active site.

Activators

Substances that increase enzyme activity.

Inhibitors

Substances that decrease or inhibit enzyme activity, which can be reversible or irreversible depending on their binding strength.

Regulation of Chemical Reactions

Allosteric enzymes play a crucial role in regulating chemical reactions.